Today, the wallet has become a popular accessory to permit people to carry important papers and certificates, valuables, and the like. Thus, if one's wallet should ever become lost or stolen, it would cause the user to suffer serious economic loss not to mention inconveniences. Unfortunately, since modern morals have been deteriorating and pickpocketing has increased, the person who carries a wallet is liable to be a target for the unlawful activities of the pickpocket or snatcher. In view of the above facts, the inventor has, through careful and long studies, developed the present invention so as to prevent one's wallet from being lost without causing inconvenience during normal use.